>>12811142axions are kinda cool so i will bump this thread with a serious reply as opposed to the shut posters and schizos here.
there are a few different kinds of axions: QCD (Peccei-Quinn) axions, axions from string theory, and others.
as far as they are understood, axions interact very weakly with normal matter and one another. so they could fill the role of dark matter for sure. however, they are often very very light so they are very similar to neutrinos in a lot of respects. so maybe not too interesting phenomenologically.
theoretically though they might be very promising. Peccei-Quinn axions help to resolve the strong CP problem. in string theory, axions are associated with the sector responsible for the moduli space of compactifications. therefore the discovery of axions might well help us to understand how string theory goes from being a 10 dimensional theory into a compactified 4D universe and why the families of particles we know about are the way they are
